pgsql: Add PageData C type

Add PageData C type

This adds the C type PageData and makes the existing type Page a
pointer to it. This follows the usual PostgreSQL C type naming scheme
of Foo/FooData pairs. (Prior to commit ddbba3aac86, PageData existed
as an unrelated type.) The type definitions are compatible, so this
doesn't change anything except some of the naming.

Discussion: /messages/by-id/692ee0da-49da-4d32-8dca-da224cc2800e@eisentraut.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6e4df237fbb532e7807cdd97f8b0b0d85093b9ee

Modified Files
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src/include/storage/bufpage.h | 3 ++-
src/tools/pgindent/typedefs.list | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)